It is the first week that if you want a booster, you can get one now. And you can mix and match. The CDC has given the green light for the Moderna and J&J booster shots. The CDC also approved mixing and matching brands. Parkland Hospital Chief Medical Officer Dr. Joseph Chang says if you have the single J&J or the two Moderna or Pfizer, they consider you fully vaccinated. If you are 18 and older, you can get a J&J booster. Just remember, follow the recommended CDC gap between your last shot and your booster.